Pipettes that are conventionally used in laboratories comprise a replaceable tip container or tip, where the substance to be dosed is first sucked in. The tip is usually conical and is attached by friction to the respectively conical bottom end of the pipette suction cylinder for sucking liquid into the tip through its lower end. Traditionally the tips are fastened manually to the pipette. Generally the tips are wider at the top, and they are placed in holes provided in a particular tip rack, said holes being smaller than said wider top parts. From the rack, the tips can then be picked by pressing the lower end of the pipette onto the top part of the tip without manually touching the tip. Thus also in the case of a multichannel pipette, all tips can be replaced at the same time, when the rack includes tips in rows, each row containing exactly the required number of tips. Naturally the rack supplied along with the tips costs money, adds to the volume of the dispatch and increases the amount of waste created in the laboratory.
In the patent application WO 95/08392 (corresponding to Lemieux et al. U.S. Pat. No. 5,441,702) there is introduced a refill pack to be used together with the tip rack, from which refill pack the empty tip rack can be refilled. The refill pack includes several layers of tips stacked in a telescopic fashion. The lowest layer rests in holes provided in a carrier plate, wherefrom it is pushed through the plate to the rack positioned underneath. In the embodiment illustrated in FIG. 7, the top layers always rest on the lowest layer. At the edges of the holes provided in the carrier plate, there are formed radial cuts, so that in between said cuts, there are left flexible strips, and the tips are supported by said strips. The tip rack to be refilled is positioned underneath the refill pack, and when the tips are pressed downwardly from above, the strips give way and the tips are pushed through the holes to the holes provided in the tip rack and located underneath. For pressing, the pack is provided with a special push plate located on top of the topmost tip layer. The refill pack is surrounded by a shell, and the shell bottom comprises a widening skirt that facilitates the focusing of the pack above the tip rack. As the tip layers are one by one released from the bottom of the pack, the push plate is lowered down layer by layer inside the pack. In order to release the last layers, the user must put his hand deep into the pack. In spite of this, the refill packs available in the market have so far been only of the type illustrated in FIG. 11 of said publication (FIG. 10 of the corresponding U.S. patent), with separate support plates additionally provided in between the tip layers.